Branch connections as commonly known are provided by a plumbing tee and by threading pipes into the branches of the tee.
Also known in the art are branch connectors that can be secured to a main plumbing line by straps or other fittings, and which communicate with the main plumbing line through a hole drilled through the exterior surface of the main pipe line, the branch connector being sealed to the outer surface of the main line.
Such branch connectors have been successfully employed in the fabrication of fire extinguishing sprinkler systems. However, the known branch connectors are encumbered with the disadvantage that two hands must be employed for assembling the branch connector onto the main pipe, this involving the holding of the branch connector in one hand while the securing strap is attached to the branch connector. While this poses no particular problem in locations that are readily accessible, it does pose considerable problems in the assembly of such branch connectors in difficult locations, such as high above a workshop floor, which is a typical location of such sprinkler heads.
Branch connectors that are a snap-fit onto the main pipeline have been previously proposed. Typical of such snap-on branch connectors are ones manufactured by Spraying Systems Co. of Wheaton, Ill., U.S.A. and by Uni-Spray of Waterloo, Ontario, Canada.
The snap-fit branch connectors manufactured by those firms are employed for the securement of spray nozzles to a low pressure pipeline. While the snap-fit branch connectors referred to are eminently suited to their intended purpose, which is one in which relatively low pressures exist in the pipeline, they are not suited to their employment in fire extinguishing systems.
In a fire extinguishing system, the sprinkler heads are exposed to a continuous high static pressure within the pipeline, which exists at all times and possibly for many years, and until such time that the sprinkler heads are actuated by a fire condition.
The prior known quick connect branch connectors each employ spring clips that can be snapped over the main pipeline, and, which maintain the quick connect branch connector attached to the main pipeline exclusively by the stored spring force in the spring clips.
As will be apparent, the pressure at which the connection will fail is determined by the spring force that can be exerted on the connectors by the spring clips. Thus, the use of such known quick connect branch connectors is limited to relatively low pressure applications for supporting spray nozzles that are exposed to dynamic pressure loading. In a fire extinguishing system the sprinkler heads are continuously exposed to a high static pressure loading of a much greater magnitude than that encountered in a spraying system.
Further considerations present themselves in the assembly of fire extinguishing sprinkler systems. A major one of those considerations is that the sprinkler heads must be attached to the main pipeline in a manner that prohibits accidental or intentional removal of the sprinkler head at the time the main pipeline is under pressure. This consideration, of course, applies in all other plumbing applications in which the pipeline is under pressure, particularly in the event that noxious or hazardous fluids are being conveyed by the pipeline.